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Immunoglobulins in milk from cows immunized with oral strains of Actinomyces, Prevotella, Porphyromonas, and Fusobacterium.

Immunization of pregnant cows with bacteria leads to the presence of high concentrations of specific antibodies in colostrum and milk. A total of 14 cows was immunized with single strains of heat-killed oral bacteria or pools of strains of Actinomyces, Porphyromonas, Prevotella, and Fusobacterium. Two cows were treated with adjuvant alone. The mean percentages of IgG1, IgG2, IgM, and IgA in all of the milks were 83.8, 3.8, 9.3, and 3.1, respectively. ELISA and whole cell agglutination assays demonstrated high titers in the milks from the cows immunized with either individual strains or the bacterial pools. The highest titers determined by ELISA belonged to the IgG1 isotype and in several milks were 64-fold greater than titers in milk from cows treated with adjuvant alone. The concentrations of all antibodies and the titers determined by ELISA and whole cell agglutination assays markedly decreased from the first to the sixth milkings. The functional specificity of the antibodies was demonstrated by agglutination tests against a wide range of bacteria including members of Actinomyces, Fusobacterium, Porphyromonas, Prevotella, Streptococcus, Eubacterium, Propionibacterium, Peptostreptococcus, Bacteroides, Actinobacillus, Haemophilus, Capnocytophaga, and Wolinella. Minimal cross-reactions with bacteria in other genera were observed with all of the milks. High-titer milk preparations have been obtained from immunized cows, and the capacity of the bovine antibodies to agglutinate target bacteria indicates their potential usefulness in oral passive immunization studies.

Actinomyces

Phagocytosis of Porphyromonas gingivalis and Prevotella intermedia by human polymorphonuclear leukocytes in clots formed from human plasma or purified fibrinogen.

We have studied the polymorphonuclear leukocyte (PMN) phagocytosis of Porphyromonas gingivalis (Bacteroides gingivalis) and Prevotella intermedia (Bacteroides intermedius) in three-dimensional fibrin meshworks formed by either clotting human plasma or by clotting purified fibrinogen with human serum incorporated. PMN phagocytosis of rhodamine isothiocyanate-labelled P. gingivalis in the fibrinogen clot was 43 +/- 6% and in the plasma clot was 62 +/- 10%; for P. intermedia the values were 15 +/- 10% and 63 +/- 10%, respectively. This showed that phagocytosis in the plasma clot system was significantly higher than in the fibrinogen clot system. However, increasing the concentration of serum in the fibrinogen clot abolished this difference, suggesting that opsonin levels determine PMN function in this assay. Labelling the bacteria with a different fluorochrome, fluoroscein isothiocyanate, reduced the level of PMN phagocytosis in both three-dimensional systems but phagocytosis was unaffected when PMN were adherent to glass. It would appear that PMN phagocytosis in three-dimensional systems can vary depending on the composition of the clot and the fluorochrome used to label the bacteria.

Analysis of Variance

Lipopolysaccharides of Bacteroides intermedius (Prevotella intermedia) and Bacteroides (Porphyromonas) gingivalis induce interleukin-8 gene expression in human gingival fibroblast cultures.

Lipopolysaccharides (LPS) prepared from Bacteroides intermedius (Prevotella intermedia) and Bacteroides (Porphyromonas) gingivalis by hot phenol-water extraction induced interleukin-8 (IL-8) mRNA in normal human gingival fibroblast cultures, as demonstrated by Northern (RNA) blot analysis. IL-8 mRNA levels began to increase after a 2-h exposure, reached a maximum after 12 h, and then dropped to the unstimulated level at 48 h. IL-8 mRNA levels were also enhanced in a dose-dependent manner. By contrast, LPS specimens from various Salmonella species with S and R chemotypes and bacterial [corrected] and synthetic lipid A preparations did not increase IL-8 mRNA levels in fibroblasts. Although recombinant human IL-1 alpha induced IL-8 mRNA expression in fibroblast cultures, an antiserum to recombinant human IL-1 alpha did not decrease the IL-8 mRNA accumulation induced by B. intermedius LPS. Fibroblasts primed with natural human gamma interferon (IFN-gamma) expressed higher IL-8 mRNA levels upon stimulation with B. intermedius LPS, but not with Salmonella LPS, compared with nontreated cells. Natural human IFN-beta exhibited a similar priming effect on the fibroblasts, and antiserum to IFN-beta added to the cultures together with B. intermedius LPS decreased the IL-8 mRNA levels. Therefore, endogenous IFN-beta enhanced IL-8 mRNA production in response to B. intermedius LPS in fibroblasts.

Bacteroides

Potential biomarkers for human Ascending aortic aneurysm identified through metagenomic and metabolomic analyses: A case-control study.

INTRODUCTION: Ascending aortic aneurysm (AsAA) is a high-risk cardiovascular condition; recent research indicates a possible association between gut microbiota, plasma metabolites, and the pathogenesis of AsAA. OBJECTIVE: This study aims to investigate the compositional and metabolic alterations in the gut microbiota of AsAA patients to identify potential biomarkers for AsAA. METHODS: This study enlisted 72 participants, comprising 44 individuals with AsAA and 28 healthy controls. All participants underwent examination for clinical features, and fecal and plasma samples were obtained for metagenomic and metabolomic studies. RESULTS: Metagenomic analysis revealed a significant reduction of 23 bacterial species in AsAA patients, including Bifidobacterium adolescentis, Bifidobacterium longum, Lactiplantibacillus plantarum, Enterococcus faecalis, and Streptococcus thermophilus, while 52 bacterial species, such as Prevotella copri, Phascolarctobacterium faecium, and Eubacterium ventriosum, were found to be enriched. Furthermore, we identified seven microbial co-abundance groups (CAGs), of which three (predominantly comprising Roseburia, Agathobacter, and Prevotella) were significantly elevated in AsAA patients, whereas one (predominantly comprising Escherichia) was substantially diminished. KEGG pathway enrichment analysis indicated that the biosynthesis of unsaturated fatty acids pathway displayed the most pronounced differences between groups. Metabolomics data revealed that 22 metabolites, including ceramides, were significantly elevated, while 8 metabolites, such as threonine, were notably downregulated. Moreover, clinical indicators like C-reactive protein (CRP) and complement components C3 and C4 have shown strong correlations with specific gut microbiota (Streptococcus, Prevotella) and plasma metabolites (threonine, ceramides). These findings indicate that inflammatory responses, metabolic dysregulation, and gut microbiota imbalance are pivotal in the etiology of AsAA. CONCLUSION: This study demonstrates substantial alterations in gut microbiota composition and plasma metabolites in patients with AsAA. Prevotella and ceramides exhibit potential as biomarkers for AsAA diagnosis. Furthermore, a synergy of Prevotella and ceramides may function as a potent disease prediction classifier, offering novel perspectives on the early diagnosis and targeted treatment of AsAA.

Humans

Multi-omics revealed the effects of rumen to blood path on early lactation performance in transition dairy cows.

BACKGROUND: The transition period is vitally important to the life cycle of dairy cows. However, the function of the microbiota during both pre- and post-partum and their relationship with ruminal, plasma, and milk metabolites still require systematic investigation. To address this, the 7 highest- and 7 lowest-performing animals among a cohort of 100 dairy cows were selected based on their postpartum energy-corrected milk yield. Rumen fluid and plasma samples were collected during both pre- and post-partum periods, whereas milk samples were obtained postpartum. Shotgun metagenomics of rumen contents in addition to metabolomics of rumen, plasma, and milk samples were performed to evaluate the associations between ruminal microbes and early lactation performance in transition dairy cows. RESULTS: Compared with prepartum cows, postpartum high-yield cows had greater concentrations of ruminal volatile fatty acids and plasma total bile acid. Moreover, plasma urea nitrogen and most amino acids, peptides, and their derivatives in plasma and milk were increased in postpartum high-yield cows, relative to postpartum low-yield cows. Metagenomic analysis revealed that the relative abundances of several species within the Prevotella, Succinimonas, Succinatimonas, and Methanosphaera increased, while other bacteria belong to Alistipes and Bacteroides, and archaeal Methanobrevibacter species decreased in postpartum cows, particularly in postpartum high-yield cows. Co-occurrence network and correlation analysis suggested that Prevotella and Succinatimonas were negatively correlated to Alistipes, Bacteroides, and Methanobrevibacter, potentially contributing to the nutritionally efficient phenotype of postpartum high-yield cows. A metabolic pathway analysis of our metagenomic data revealed that postpartum high-yield cows possessed more microbial genes involved in starch utilization and amino acid synthesis, while a wide range of microbial genes involved in cellulose utilization, acetogenesis, and amino acid degradation were found in prepartum cows with low-yield in postpartum. A structural equation model analysis showed that the increased relative abundances of Prevotella tf.2-5 and Succinatimonas CAG_777 were related to greater concentrations of plasma chenodeoxycholic acid glycine conjugate, milk 5-Methoxytryptophan, and energy-corrected milk yield. Finally, pan-genomic analysis confirmed that Alistipes, Bacteroides, and Methanobrevibacter possess genetic conservation of both hydrogenases and dehydrogenases, which may contribute to energy loss in the rumen via hydrogen dissipation. CONCLUSION: In summary, our findings provide a fundamental understanding of how microbiome-dependent mechanisms contribute to early lactation performance in dairy cows during the transition period. The increased abundance of Prevotella, Succinimonas, and Succinatimonas in postpartum cows suggest that they are important microbes during the transition period and may help in coping with metabolic challenges, while improving nutrient utilization efficiency during this period. Our study underscores the importance of the ruminal microbiome during the transition period and highlights the need for rumen-based nutritional intervention strategies to improve production efficiency in ruminants. Video Abstract.

Animals

Major depletion of insulin sensitivity-associated taxa in the gut microbiome of persons living with HIV controlled by antiretroviral drugs.

BACKGROUND: Persons living with HIV (PWH) harbor an altered gut microbiome (higher abundance of Prevotella and lower abundance of Bacillota and Ruminococcus lineages) compared to non-infected individuals. Some of these alterations are linked to sexual preference and others to the HIV infection. The relationship between these lineages and metabolic alterations, often present in aging PWH, has been poorly investigated. METHODS: In this study, we compared fecal metagenomes of 25 antiretroviral-treatment (ART)-controlled PWH to three independent control groups of 25 non-infected matched individuals by means of univariate analyses and machine learning methods. Moreover, we used two external datasets to validate predictive models of PWH classification. Next, we searched for associations between clinical and biological metabolic parameters with taxonomic and functional microbiome profiles. Finally, we compare the gut microbiome in 7 PWH after a 17-week ART switch to raltegravir/maraviroc. RESULTS: Three major enterotypes (Prevotella, Bacteroides and Ruminococcaceae) were present in all groups. The first Prevotella enterotype was enriched in PWH, with several of characteristic lineages associated with poor metabolic profiles (low HDL and adiponectin, high insulin resistance (HOMA-IR)). Conversely butyrate-producing lineages were markedly depleted in PWH independently of sexual preference and were associated with a better metabolic profile (higher HDL and adiponectin and lower HOMA-IR). Accordingly with the worst metabolic status of PWH, butyrate production and amino-acid degradation modules were associated with high HDL and adiponectin and low HOMA-IR. Random Forest models trained to classify PWH vs. control on taxonomic abundances displayed high generalization performance on two external holdout datasets (ROC AUC of 80-82%). Finally, no significant alterations in microbiome composition were observed after switching to raltegravir/maraviroc. CONCLUSION: High resolution metagenomic analyses revealed major differences in the gut microbiome of ART-controlled PWH when compared with three independent matched cohorts of controls. The observed marked insulin resistance could result both from enrichment in Prevotella lineages, and from the depletion in species producing butyrate and involved into amino-acid degradation, which depletion is linked with the HIV infection.

Humans

Gene cloning of Porphyromonas gingivalis specific antigens recognized by serum of adult periodontitis patient.

1. Porphyromonas gingivalis is believed an important pathogen of adult periodontitis. A gene library of P. gingivalis 381 was constructed in lambda phage vector L47.1. The library was probed with serum obtained from patients of severe adult periodontitis. Two clones, lambda MDBG101 and lambda MDBG103 which were expressed, 200 and 160 kDa respectively, were selected and further studied. 2. The expressed antigens in these two clones were also reacted with rabbit antiserum against whole cells, capsular fraction and cell surface fraction of P. gingivalis. 3. Genes coding protein antigens in lambda MDBG101 and lambda MDBG103 were subcloned into high-copy-number plasmid vector pACYC184 and subclones obtained were designated as MD101 and MD103. Recombinant plasmids, pMD101 and pMD103, differed in their restriction endonuclease digestion. 4. Immunodiffusion analysis showed that cloned proteins from MD101 and MD103 reacted with antiserum against P. gingivalis but did not react with antiserum against Prevotella intermedia, Prevotella loescheii and Prevotella asaccharolyticus. 5. These data suggest that P. gingivalis species-specific antigens has been successfully cloned and expressed in Escherichia coli. Since these cloned specific antigens were recognized by adult periodontitis patient sera, the recombinant antigen will be useful material for the development of serodiagnosis of P. gingivalis infection in adults periodontitis.

Adult

Rumen microbiota-associated stress alleviation by creatine pyruvate in newly received cattle: a multi-omics study.

BACKGROUND: Stress experienced by newly received cattle is a significant challenge in the beef industry, frequently resulting in weakened immune responses and impaired growth. The rumen microbiota is essential to host health, and its imbalance can exacerbate stress. This study investigates the mechanisms by which creatine pyruvate (CrPyr) mitigates stress in newly received cattle through multi-omics approaches, including metagenomics, metabolomics, in vitro and in vivo experiments, and rumen microbiota transplantation (RMT) in mice. RESULTS: Our results revealed that CrPyr significantly reduces stress-related hormones (cortisol and adrenocorticotropic hormone) and inflammatory markers (IL-6, IL-1&#x3b2;, and TNF-&#x3b1;), and enhanced antioxidant capacity (SOD: 57.38 versus 46.93&#xa0;U/mL, P&#x2009;<&#x2009;0.05; GSH-Px: 305.87 versus 217.07&#xa0;U/mL, P&#x2009;<&#x2009;0.05; T-AOC: 9.62 versus 7.66&#xa0;U/mL, P&#x2009;<&#x2009;0.05). Metagenomic analysis demonstrated that CrPyr increased Prevotella abundance, a key rumen bacterium involved in volatile fatty acid (VFA) production, and enriches metabolic pathways associated with energy metabolism (ATP synthesis, and pyruvate metabolism) and antioxidant defense (glutathione metabolism, FC&#x2009;=&#x2009;1.08, P&#x2009;<&#x2009;0.05). In vitro and in vivo experiments, as well as RMT studies in mice, further validate these findings, demonstrating that CrPyr promote VFA synthesis and increased ATP production through the electron transport phosphorylation pathway. CONCLUSIONS: CrPyr modulates the abundance of ruminal Prevotella in transport-stressed cattle to enhance glutathione and VFA metabolism and to accelerate ATP and nucleotide synthesis, thereby alleviating stress in newly received cattle. This multimodal approach established CrPyr as an effective nutritional intervention that improves rumen function and increases livestock productivity. Video Abstract.

Animals

The management of acute, serous and chronic otitis media: the role of anaerobic bacteria.

Otitis media (OM) is a common childhood disease and one which can cause significant morbidity. A knowledge of the pathogens responsible for OM enables the most appropriate treatment regimen to be selected and thus minimizes further complications which may require hospital admission and surgery. The microbiology of acute, serous and chronic OM is reviewed, with particular regard to the role of anaerobic bacteria. Anaerobes, mainly Gram-positive cocci, have been recovered from 25% of the ear aspirates of patients with acute otitis media. In a study of serous OM, anaerobic bacteria were recovered in 12% of the culture-positive aspirates. The predominant anaerobes were Gram-positive cocci and pigmented Prevotella. Several studies have reported the recovery of anaerobes from about 50% of patients with chronic OM and those with cholesteatoma. The predominant anaerobes were Gram-positive cocci, pigmented Prevotella, Porphyromonas sp., Bacteroides spp. and Fusobacterium spp. Many of these organisms produce beta-lactamase which might have contributed to the failure of the patients to respond to penicillins. The appropriate antimicrobial therapy for acute, serous and chronic otitis media is discussed.

Acute Disease

Contribution of a combined approach using refined enterotyping and non-negative matrix factorization (NMF) to the characterization of the gut microbiota in Tunisia, North Africa.

This pilot study aimed to assess the enhanced capabilities of a combined approach using refined enterotyping and non-negative matrix factorization (NMF) for identifying specific microbiota patterns in healthy adults in Tunisia. Shotgun metagenomic sequencing was performed on 21 stool samples. Taxonomic classification was carried out using Kraken2, followed by Bracken analysis. Enterotype (ET) assignment was performed using a publicly available, reference-based classification tool involving Fuzzy-k-means (FKM) clustering. Next, NMF was applied to identify 'enterosignatures' (ESs). The FKM approach revealed a co-dominance of Prevotella-ET (P-ET, 57%) and Firmicutes-ET (F-ET, 38%) with 41% of P-ET samples exhibiting a significant deviation from the reference enterotype center. These latter had a lower proportion of Prevotella-ES and a higher proportion of Bacteroides/Phocaeicola-, Firmicutes- and/or Bifidobacterium-enriched ESs. The F-ET samples were differentially enriched by Blautia (P =&#xa0;0.007) and Vescimonas (P =&#xa0;0.007). NMF revealed within this group, a candidate Firmicutes-associated ES driven by Blautia and encompassing Vescimonas, Akkermansia, and Methanobrevibacter. These findings demonstrate the combined power of refined enterotyping and NMF in characterizing gut microbiota, providing a key methodology for future large-scale research. However, our relatively small sample size limits statistical power and biological interpretation, making this study exploratory in nature. Candidate ES requires validation in larger independent datasets.

Humans

Antibacterial activity of dental implant metals.

This study was conducted to investigate the specific in vitro antibacterial effect of seven dental implant metals on oral bacteria which have often been identified in failing implants. The metals chosen for evaluation were titanium, chromium, cobalt, aluminum, iron, gold, and vanadium. These metals were selected because they are contained in many commonly used dental implants. The bacteria selected for this study included isolates of Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, Prevotella melaniogenica, Actinobacillus actinomycetemcomitans, Actinomyces naeslundii, and Actinomyces viscosus. Sets of tubes containing either supplemented trypticase soy broth, brain-heart infusion-yeast extract, or brain-heart infusion-yeast extract with 5 percent defibrinated rabbit blood were aseptically prepared with doubling dilutions of the seven metals starting at an initial concentration of 500 micrograms/ml and terminating at 0 microgram/ml. Cultures of each organism were inoculated into each set of broth tubes containing all concentrations of metals. Tubes were incubated either anaerobically or in an atmosphere of 5 percent carbon dioxide for 48 hours at 35 degrees C and then assayed for ATP content which was proportional to the viable cellular biomass. The results showed that, although being bacteria and concentration dependent, all seven metals suppressed the growth of each organism. The rank order of antibacterial activity expressed by dental implant metals was gold > titanium > cobalt > vanadium > aluminum > chromium > iron.

Actinomyces

The selective culture and enrichment of major rumen bacteria on three distinct anaerobic culture media.

Ruminants play an important part in global food security, but also emit methane, which contributes to global warming. Rumen microbes strongly influence the energy retention efficiency from the host's plant-based diet and produce methane as a by-product. While thousands of novel microbial genomes have been assembled from metagenomic sequence data, their culturability is ill-defined. Here, different media (Med10, Med2, and MedTC) were used to isolate co-cultures of microbes from rumen fluid. Thirty-four OTUs were identified belonging to the phyla Bacillota (75.28 &#xb1; 6.34%), Bacteroidota (19.99 &#xb1; 4.85%), Pseudomonadota (2.46 &#xb1; 2.01%), and Actinomycetota (2.09 &#xb1; 1.07%). The most abundant genera were Selenomonas (28.08 &#xb1; 11.71%), Streptococcus (22.67 &#xb1; 6.06%), Prevotella (18.71 &#xb1; 4.02%), and unclassified Lachnospiraceae (11.50 &#xb1; 2.54%), and 31 significantly enriched on at least one medium, with each medium successfully culturing a distinct range of microbes. The composition of the source rumen fluid was vastly different from those cultured. Bacteroidota (52.53 &#xb1; 5.10%) predominated, with Bacillota (41.00 &#xb1; 3.96%), Methanobacteriota (5.12 &#xb1; 1.94%), Pseudomonadota (1.22 &#xb1; 0.78%), and Actinomycetota (0.12 &#xb1; 0.08%) comprising the rest. The most abundant genera were Prevotella (29.13 &#xb1; 4.16%), Butyrivibrio (18.21 &#xb1; 2.08%), Succiniclasticum (15.57 &#xb1; 5.03%), unclassified Bacteroidetes (13.91 &#xb1; 1.67%), and unclassified Prevotellaceae (9.50 &#xb1; 2.01%). These data further emphasize the importance of using defined media to select for different microbial taxa. This is essential to understand the complex workings of the rumen microbes to enhance digestion efficiency and reduce the loss of energy that could potentially be utilized by the host.IMPORTANCEThis research demonstrates that using a range of culture media, containing a wide variety of substrates, can lead to the culture of key rumen microbes. The knowledge of which of these microbes is selectively enriched on each medium is essential to understand how to grow these microbes in co-culture and isolate them in pure culture for further investigation. In addition, this research shows the stark disparity between the population of rumen microbes grown in co-culture and those found in the rumen itself. This further demonstrates the need for a targeted approach to growing and isolating these microbes. Learning how these microbes respond to culture media with different nutritional compositions will lead to a better understanding of the rumen microbiota, and this research provides a valuable insight into how selective media can target the enrichment of different microbes. This knowledge will contribute to increasing ruminant digestion efficiency and reducing methane production.

Rumen

Consumption of traditional Sardinian fermented milk promotes changes in the rat gut microbiota composition and functions.

BACKGROUND: Fermented milk products are part of the staple diet for many Mediterranean populations. Most of these traditional foods are enriched with lactobacilli and other lactic acid bacteria, as well as with metabolites resulting from lactose fermentation. Currently, there is very little scientific knowledge on how dietary supplementation with fermented milk affects the composition of the gut microbiota and its metabolic activities. RESULTS: We integrated 16&#xa0;S rRNA gene-based taxonomic profiling with metaproteomics-based functional analysis to investigate gut microbiota changes in rats exposed to an 8-week dietary supplementation with casu axedu, a traditional fermented milk produced within rural communities in Sardinia (Italy). Several microbial taxa showed a significantly increased abundance at the end of the dietary treatment, including Phascolarctobacterium, Prevotella, Blautia glucerasea, and Lactococcus lactis, while Bacteroides dorei and Helicobacter rodentium were decreased compared to the control rats. Metaproteomic analysis highlighted a striking reshaping of the Prevotella proteome in agreement with its blooming in casu axedu-fed animals, suggesting an increase of the glycolytic activity through the Embden-Meyerhof-Parnas pathway over the Entner-Doudoroff pathway. Moreover, an increased production of enzymes involved in succinate biosynthesis was observed, which in turn significantly boosted the abundance of Phascolarctobacterium and its production of propionate. Fermented milk consumption also promoted microbial synthesis of branched chain essential amino acids L-valine and L-leucine. Finally, metaproteomic data indicated a reduction of bacterial virulence factors and host inflammatory markers, suggesting that the consumption of casu axedu can have beneficial effects on the gut mucosa health. CONCLUSIONS: Our integrated multi-omics approach reveals that dietary supplementation with the traditional Sardinian fermented milk, casu axedu, induces significant shifts in the rat gut microbiota composition and function, characterized by the enrichment of beneficial taxa and metabolic pathways associated with improved gut health and reduced inflammation.

Animals

Influence of creatine pyruvate on newly received cattle: insights from metagenomics and metabolomics.

Transport stress is a critical factor affecting the health and growth performance of beef cattle, potentially leading to oxidative stress, inflammation, and metabolic disorders. Creatine pyruvate (CrPyr), as a potential stress alleviator, has unclear mechanisms of action. We monitored the growth of 17 Simmental calves (control, n&#x2009;=&#x2009;8; CrPyr, n&#x2009;=&#x2009;9) over 30 days post-transportation, collecting rumen and blood samples on days 1/4, and 30. This study aims to investigate the effects of CrPyr on the growth performance, rumen microbiome, and metabolome of calves subjected to transport stress. Results showed that CrPyr increased average daily gain and antioxidant capacity, while reducing the level of stress hormones and inflammation. In the 4 days post-transport, CrPyr mainly increases Ruminococcus abundance to boost ruminal nitrogen metabolism, providing substrates for microbial protein synthesis. CrPyr also provides energy for the proliferation of Ruminococcus by regulating ATP synthesis genes (ATPVC) and enriching purine metabolism products. Meanwhile, it strengthens the host's amino acid metabolism, especially aspartate, to enhance antioxidative capacity. By day 30, CrPyr primarily boosts Prevotella abundance to regulate VFA synthesis, supplying host energy. It regulates the ATP synthesis gene ATPF0A and enriches purine metabolism products, supporting Prevotella growth. Increased citric acid and ATP levels further aid host growth. The findings distinctly demonstrate that the mechanisms by which CrPyr alleviates transport stress through the regulation of the rumen microbiome and metabolome, and confirms that its effects are time-dependent. These findings provide a theoretical basis for the development of stress-alleviation strategies based on CrPyr and hold significant implications for enhancing the health and production performance of beef cattle.

Animals

Fecal microbiota transplantation improves anti-PD-1 inhibitor efficacy in unresectable or metastatic solid cancers refractory to anti-PD-1 inhibitor.

The gut microbiome significantly influences immune responses and the efficacy of immune checkpoint inhibitors. We conducted a clinical trial (NCT04264975) combining an anti-programmed death-1 (PD-1) inhibitor with fecal microbiota transplantation (FMT) from anti-PD-1 responder in 13 patients with anti-PD-1-refractory advanced solid cancers. FMT induced sustained microbiota changes and clinical benefits in 6 of 13 patients, with 1 partial response and 5 stable diseases, achieving an objective response rate of 7.7% and a disease control rate of 46.2%. The clinical response correlates with increased cytotoxic T&#xa0;cells and immune cytokines in blood and tumors. We isolated Prevotella merdae Immunoactis from a responder to FMT, which stimulates T&#xa0;cell activity and suppresses tumor growth in mice by enhancing cytotoxic T&#xa0;cell infiltration. Additionally, we found Lactobacillus salivarius and Bacteroides plebeius may inhibit anti-tumor immunity. Our findings suggest that FMT with beneficial microbiota can overcome resistance to anti-PD-1 inhibitors in advanced solid cancers, especially gastrointestinal cancers.

Adult

Lesion-specific oral microbiome signatures and predicted carcinogenic pathways in oral squamous cell carcinoma: a paired-site study in Pakistan.

BACKGROUND: Oral squamous cell carcinoma accounts for over 90% of oral neoplasms. Despite therapeutic advances, the lack of reliable, non-invasive biomarkers and delayed diagnosis continues to impede effective clinical management. By combining paired lesion and non-lesion sampling with predictive metagenomics analysis, our study addresses this gap and advances the current understanding of microbiome&#x2012;tumor interactions. METHODS: We analyzed 92 buccal swab samples from 39 OSCC patients and 14 healthy controls using 16S rRNA gene (V3-V4) sequencing. Taxonomic profiling was conducted using QIIME2 and SILVA/eHOMD databases, functional pathways were predicted using PICRUSt2, and hub taxa were identified through co-abundance network analysis. RESULTS: Microbial community structure differed significantly across lesion, non-lesion, and healthy sites (PERMANOVA, p&#x2009;=&#x2009;0.001). Lesions were enriched with Selenomonas infelix and Treponema vincentii, while healthy controls harbored Streptococcus oralis and Gemella haemolysans. Co-abundance network analysis revealed lesion-specific hub species, notably T. vincentii, strongly correlated with predicted activation of pyrimidine biosynthesis pathways (r&#x2009;=&#x2009;0.69, q&#x2009;<&#x2009;1E-6), suggesting predicted metabolic alterations in the tumor microenvironment. Non-lesion sites were also characterized by two hub species, Prevotella melaninogenica and Segatella oulorum. CONCLUSION: Our findings define a lesion-specific microbial signature of OSCC characterized by the depletion of health-associated taxa, enrichment of pro-inflammatory pathobionts, and predicted associations with metabolic pathways implicated in carcinogenesis. These alterations reflect a predicted functionally altered tumor microenvironment.

16S rRNA gene